vm: replace vm-region with address-space

address-space is a non-recursive data structure, which contains a flat list of vm_areas representing
mapped vm-objects.

userspace programs can no longer create sub-address-spaces. instead, they can reserve portions of
the address space, and use that reserved space to create mappings.

kernel/handle.c

@@ -1,9 +1,9 @@
+#include <kernel/address-space.h>
 #include <kernel/handle.h>
 #include <kernel/libc/string.h>
 #include <kernel/object.h>
 #include <kernel/sched.h>
 #include <kernel/util.h>
-#include <kernel/vm-region.h>
 #include <kernel/vm.h>
 #include <mango/types.h>
 
@@ -195,11 +195,11 @@ struct handle *handle_table_get_handle(
 }
 
 kern_status_t handle_table_transfer(
-	struct vm_region *dst_region,
+	struct address_space *dst_region,
 	struct handle_table *dst,
 	kern_msg_handle_t *dst_handles,
 	size_t dst_handles_max,
-	struct vm_region *src_region,
+	struct address_space *src_region,
 	struct handle_table *src,
 	kern_msg_handle_t *src_handles,
 	size_t src_handles_count)
@@ -214,7 +214,7 @@ kern_status_t handle_table_transfer(
 			= (virt_addr_t)src_handles + (i * sizeof src_handle);
 		virt_addr_t dst_handle_addr
 			= (virt_addr_t)dst_handles + (i * sizeof dst_handle);
-		status = vm_region_read_kernel(
+		status = address_space_read(
 			src_region,
 			src_handle_addr,
 			sizeof src_handle,
@@ -223,7 +223,7 @@ kern_status_t handle_table_transfer(
 
 		if (status != KERN_OK) {
 			src_handle.hnd_result = KERN_OK;
-			vm_region_write_kernel(
+			address_space_write(
 				src_region,
 				src_handle_addr,
 				sizeof src_handle,
@@ -244,7 +244,7 @@ kern_status_t handle_table_transfer(
 		if (!src_entry) {
 			status = KERN_INVALID_ARGUMENT;
 			src_handle.hnd_result = KERN_INVALID_ARGUMENT;
-			vm_region_write_kernel(
+			address_space_write(
 				src_region,
 				src_handle_addr,
 				sizeof src_handle,
@@ -299,13 +299,13 @@ kern_status_t handle_table_transfer(
 
 		src_handle.hnd_result = status;
 
-		vm_region_write_kernel(
+		address_space_write(
 			src_region,
 			src_handle_addr,
 			sizeof src_handle,
 			&src_handle,
 			NULL);
-		vm_region_write_kernel(
+		address_space_write(
 			dst_region,
 			dst_handle_addr,
 			sizeof dst_handle,
@@ -317,7 +317,7 @@ kern_status_t handle_table_transfer(
 		kern_msg_handle_t handle = {0};
 		virt_addr_t handle_addr
 			= (virt_addr_t)src_handles + (i * sizeof handle);
-		vm_region_read_kernel(
+		address_space_read(
 			src_region,
 			handle_addr,
 			sizeof handle,